Abrasive form and process of making the same



Patented Aug. 4, 1925.

UNITED STATES PATENT OFFICE.

PAUL KEEVER, OP WEST CHESTER, PENNSYLVANIA, ASSIGNOR TO THE WHITE HEAT PRODUCTS COMPANY, OF WEST CHESTER, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

ABRASIVE roam: AND rnocnss or MAKING THE SAME.

No Drawing. Application filed May 26,

. To all whom it may concern:

Be it known that I, PAUL Knnvnn, a citizen of the United States, residing at West Chester, in the county of Chester, State of Pennsylvania, have invented certain new and useful Improvements in Abrasive Forms and Processes of Making the Same, of which the following is a, description, reference being had to the accompanying drawing, and to l the figures of reference marked thereon.

The invention relates to new and useful improvements in abrasive forms and the process of making the same.

An object of the invention is to provide v a new composition of matter for abrasive forms, which may be molded while dry to the touch "and immediately baked or fired,

if so desired.

A further object of the invention is to provide a newcomposition of matter of the above character, wherein the grades of hardness may be varied within certain limits by the pressure applied during molding.

A further object of the invention is to provide a new process of making abrasive forms, wherein the abrasive is mixed with binders containing only suflicient water to make the mass moldable but insuflicient to make the mass wet to the touch, which mass is pressed to shape and immediately baked or fired, if so desired. j I

.The improved composition of matter for abrasive forms consists of abrasive grains and binders of such characteristics that the '35 mass may'be molded while dry to the touch and then pressed to form and immediately baked or fired, if'so desired.

Any suitable abrasive grains may be used, but I prefer to use what is known in the 40 industry as Bathite.

The binders consist, before the heat treat ment, of a temporary binder which functions to hold the mass in shape during the molding and burning, and apermanent 4 binder, such as dry powdered feldspars and dry powdered clays. For a temporary binder, I prefer to use dilute sodium silicate containing substantially one part of sodium oxide to two parts of silica, which I dilute with water until its specific gravity becomes 1550, or thereabonts. Molasses, oils or stale beer may be used as temporary binders. The various ingredients named the abrasive, temporary binder and permanent binder 1921. Serial No. 472,896.

may be used in a number of varying pro-fl nch portions to each other, but the proportlons I find to give typical abrasive wheels, or other forms, are60 to parts of Bathite; 20 to 40 parts of dry feldspars and clays, and about a parts dilute sodium silicate. I 60 Myimproved process consists of forming a mass of the'ingredients in substantially the parts stated and using only sufiicient water so that tlie mass is dry to the touch. The mass isthoroughly mixed and shaped in molds, where pressure is applied to the mass and the amount of pressure applied is varied according to the grade of hardness desired. Hardness is also controlled byvarying the proportions of the ingredients.

After the mass has been molded, it can immediately,'if so desired, be placed in an oven or kiln and baked. The. forms are notinjured, even if the temperature of the kiln at the time the ware is placed in it is 75 at baking'heat, viz: between 1800 degrees Fahrenhei-t and'2600 degrees Fahrenheit.

I would call attention particularly to the fact that my improved process is a dry process, as distinguished from the old form 30 of mud-pie wet process, wherein a great deal of water is used and wherein the forms are dried for days; Furthermore, I would call attention to the fact that the forms are pressed in the molds while the mass is substantially dry to the touch; and, as a consequence, it is not necessary to shave the form, therefore doing away with all machinery and tool work.

Then, again, I call attention to the fact that the baking of the form can be accomplished in less time than isrequired by the old wet process. Especially is this true when the forms are introduced directly into a heated kiln, a procedure considered impracticable in the Wet process. I

Furthermore, by my improved process, wherein the ingredients are molded while dry to the touch and pressed to form while in this substantially drycondition, the size of the pores and open spaces in the wheel are under control.

To illustrate, I take 565 gramsof properly mixed material and place' it'in a mold 4 in diameter to a. depth of 2 ,after pressing this material, it forms a mass 1 thick. A second batch, weighing 565 ms, depth 2% compressed to thick; a third weighing 565 grams, depth 2 compressed to 1 thick; a fourth, weighing 565 grams, depth 2% compressed to 1 thick.

- Finished Specimen depth after ii e s iil ti Maw mold com-pres' ing wheel sion.

Inches Inches 2 1% Hard. 2% 1% Medium. 2 15*} Soft. 2%,; 1 Very soft.

Specimen 1 contracted 54% Specimen 2 contracted 49% Specimen 3 contracted 44.8%

S ecimen 4contracted 41%.

ow it is evident that the difference, say, between specimens 1 and 4, or 13% (54%- 41%) must be pore space or voids.

As before mentioned, while I prefer to use for a temporary binder dilute sodium silicate, I may, however, use molasses, core oil or stale beer, but in such quantities that the mass is still dry to the touch when molded, so that throughout the process is a dry processdoing away with the drying out period.

By my improved process, a great deal of time is saved, not only in the drying out process, but in the baking process, and I also save the machine wear and tear incident to the dressing of the forms and waste of material which has been necessary heretofore, since the wheels are pressed to practically the finished size and little dressing on the finished wheel is necessary.

I am compelled to use the expression dry to the touch for lack of a better .way of expressing the idea. A handful of a proper mix, ready to be molded, can be rubbed between the hands and no moisture can be felt by the contact.

If the mix is poured in a stream falling from a small height, it will form a pile or. pyramid similar to that which would be formed by pouring dry sand or dry fine gravel in a similar manner.

Ordinary molders sand tempered with a little water, as the foundryman does, so that he can mold it properly is wetter than the mix I use, yet the tempered molders sand is ordinarily considered as dry to the touch. 7

The following illustrates how very little moisture is required in this new process. If three pounds of a properly mixed batch is placed on a steam'heated drying table and allowed to become perfectly dry, a proper amount of moisture can be addedto the three pounds by the following method. Allow water to run on your hands, so that they are thoroughly wet (as they would ordinarily be after washing them) then instead of drying the hands on a towel, use this three pounds mix to rub the moisture from the cient Water to make the mass moldable, but

hands-the hands will be quite dry and the three pound mix in question will have absorbed enough moisture from the hands to make it now moldable,, but not perceptibly wet to the touch.

Having thus described my invention, what I claim as new and desire to secure by Let-- ters Patent, is:

1. A composition of matter for making abrasive forms adapted to be set permanently by baking and to be subjected to baking heat immediately on being formed comprising abrasive grains, feldspar and clay, and a ,temporary binder, containing suiiionly such an amount of water that the mass is capable of absorbing moisture from a wet 1 hand.

2. A composition of matter for making abrasive forms adapted to be set permanently by baking and to be subjected to baking heat immediately on being formed comprising abrasive grains, clay and a temporary binder, containing suificient water to make the mass moldable, but only such an amount of water that the' mass is capable of absorbing moisture from a wet hand.

3. A composition of matter for making abrasive forms adapted to be set permanently by baking and to be subjected to baking heat immediately on being formed comprising abrasive grains, feldspar and a tempo rary binder, containing sufficient water to make the mass moldable, but only such an amount of water thatthe mass is capable of absorbing moisture from a wet hand.

4. A composition of matter for making abrasive forms adapted to be set permanently by baking and to be subjected to baking heat immediately on being formed comprising 60 to 80 parts of dry abrasive grains, 20 to 40 parts of a dry powdered permanent binder, and about 4 parts of dilute sodium silicate containing sufficient water to make the mass moldable, but only such an amount of water that the mass is capable of absorbing moisture from a wet hand.

5. A composition of matter for making abrasive forms adapted to be set permanently by baking and to be subjected to baking 11 heat immediately on being formed comprising 60 to 80 parts of dry abrasive grains, 20

to 40 parts of dry feldspars and clays, about 4 parts of dilute sodium silicate containing sufficient water to make the mass moldable, but only such an amount of water that the mass is capable of absorbing moisture from a wet hand.

6. The process of making abrasive forms capable of being fired immediately, comprising mixing dry abrasive grains,'a dry powdered permanent binder, and a temporary binder containing sufficient water to make the mass moldable, but only such an amount of water that the mass is capable of absorbing moisture from a wet hand, pressing the mass to shape and firingat a tem erature from 1800 to 2600 degrees Fahren eit. r

7. The process of making abrasive forms capable-of being fired immediately comprising mixing dry abrasive grains, dry powdered feldspars, and clays, dilute sodium silicate having sufficient water to make the mass moldable, but only such an amount of water that the mass is capable of absorbing moisture from a Wet hand, pressing the mass to shape and firingat a temperature from 1800 to 2600 degrees Fahrenheit. v8. The process of making abrasive forms v capable'of being fired immediately, compri's ing mixing 60 to '80 parts of dry abrasive grains, 20 to 40 partsof dry powdered feldspars and clays, and about 4 parts of dilute sodium silicate having sufficient water to make the -mass,moldable but only such an amount of water that the mass is capable of absorbing moisture from a wet hand, press- 1ng the mass to shape and firing at atempe'rature from i800 to 2600 degrees Fahrenheit,

9. The process of making abrasive forms comprising mlxing abrasive material, a temporary binder and a permanent binder,

. 10. The process of making abrasive fOImS comprising mixing the dry abrasive grains,-

dry feldspars and clays, and a temporary binder containing sufficient water to make the mass moldable, but only such an amount of water that the'mass is capable of absorbing moisture from a wet hand, molding the mass and subjecting the mass when molded -to regulated pressure to control the porosity and hardness of the resulting product, and

' firing.

' In testimony whereof, I affix my signature. l

. PAUL KEEVER. 

